There is a section on your Page called "Favorite Pages" which can contain links to other Facebook Pages similar to how your Fans section links to your fans' personal pages. You could use this for other organizations you're affiliated with, you partner with, etc.
To add a Page to this section:
- Go to the Page you wish to add to your Page.
- Click "Add to My Page's Favorites" located under the Page's logo.
- If you have multiple Pages, it will ask you which one you want to add it to.
- Click the "Save" button and you're all set!